1. Technical Field
The present invention relates to a pattern forming system, a pattern forming method, and an electronic apparatus.
2. Related Art
Lithography, for example, is used for the manufacturing of wirings that are used in electronic circuits or integrated circuits. Lithography requires huge facilities, such as a vacuum system, and complicated processes. Besides, in the case of using lithography, the manufacturing cost is high because the yield rate is only a few percent and the bulk of material must be thrown out. Therefore, as an alternative process to lithography, a method of patterning a droplet containing a functional material directly onto a substrate by an ink jet (a droplet discharge system) is considered. For example, a method wherein a droplet in which conductive microparticles are dispersed is applied and patterned directly onto a substrate by a droplet discharge system and then transformed into a conductive film pattern by heat treatment and laser irradiation is proposed (refer, for example, to the specification of the U.S. Pat. No. 5,132,248).
Further, a method that can be flexibly adjusted to the kind of manufacturing process to be applied in the manufacturing method of a display unit and a display device using a droplet discharge system is proposed. The method, when a relative velocity of an ink jet head to a substrate is defined as V, a discharge period of droplets as T, and a diameter of the droplets after the droplets land on the substrate and expand to wet as D, controls the relative velocity V, the discharge period T and the diameter D so as to satisfy the relation VT<D. Then, droplets are discharged on a substrate on the most appropriate discharging condition according to the kind of manufacturing process to be applied (refer, for example, to Japanese Patent Application Publication 2003-280535).
However, in the manufacturing methods of wirings or display devices according to the above-referenced methods, a platy substrate is processed into a product substrate using a plurality of steps. Therefore, a substrate needs to be moved sequentially from a location (a device) on which a certain step to be carried out to another location on which a next step to be carried out. Thus, in the above-referenced manufacturing methods, there is a problem that manufacturing cost increases because a large amount of labor and mechanism is required to transfer substrates. Specifically, in the above-referenced manufacturing methods, a large amount of labor and a complex moving mechanism such as a robot is required for allocating a surface treatment apparatus, a droplet discharge apparatus, and a drying apparatus and the like and for transferring substrates sequentially toward each of the apparatuses and aligning them precisely.
Therefore, a pattern forming system that uses a reel-to-reel substrate in tape form, each end of which is wound up with reels, and that carries out a plurality of steps, including a droplet applying step by a droplet discharge system, from the feeding of a tape form substrate until the winding up of the tape form substrate is considered. According to the system, patterns can be simply and easily formed on a plurality of pattern forming areas on a tape form substrate by first carrying out a droplet applying step to one pattern forming area and then winding up the tape form substrate to place the next pattern forming area for the droplet applying step. Finally, the tape form substrate is cut off for each pattern forming area. Thus, wirings and electronic circuits can be efficiently manufactured in volume.
However, pulling strength is generated in the longitudinal direction because the tape form substrates are formed successively in the longitudinal direction with each end wound up with reels. Therefore, there is a problem that the position adjustment of a tape form substrate during a droplet applying step and the like is difficult. Especially, position adjustments, such as moving a tape form substrate in the lateral direction or slewing a tape form substrate around a normal line, have to be done coping with the pulling strength that is generated in the longitudinal direction. Thus, it is difficult to form a pattern on a precise position.